Security systems and/or security alarm systems often use magnetic switches attached to doors, windows, and other structures to detect the unauthorized opening and/or manipulation of the door, window, or other structures. However, previous magnetic switch designs have been prone to tampering and/or have exhibited unacceptable reliability.
For example, one type of magnetic switch is a reed switch. However, these switches may be defeated by clever application of, for example, one or more external magnets. Specifically, a compact high energy magnet may be positioned in proximity to the reed switch to operate (to either open or close depending on the control scheme) the reed switch illicitly and/or without authorization. Once they have defeated the reed switch, an intruder may open and/or manipulate the door, window, or other structures without triggering the security system and/or security alarm systems.
Presently known art attempts to address this problem, but have not completely solved the problem. For example a number of magnetic switches have been proposed in the past to overcome the inherent limitation and serious deficiencies of reed switches. The following represents at least a partial list of known related art:
Date ofReference:Issued to:Issue/Publication:5,877,664Jackson, Jr.Mar. 2, 19995,929,731Jackson, Jr.Jul. 27, 19997,248,136 B2HabbooshJul. 24, 2007
The teachings of each of the above-listed citations (which does not itself incorporate essential material by reference) are herein incorporated by reference. None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as described and claimed.
U.S. Pat. No. 5,877,664 to Jackson, Jr. teaches a proximity switch system includes a switch portion, configured to connect and disconnect at least one electrical path, and a magnetically active actuator. The switch portion has a casing formed of a magnetically noninteracting material, at least one electrical contact disposed in the casing, a magnetically active armature member moveable along the casing between a first position and a second position, wherein the armature member contacts the electrical contact when in the first position to connect the at least one electrical path and the armature member being electrically isolated from the electric contact when in the second position to disconnect the at least one electrical path, and a magnetically active biasing member disposed in the casing, wherein the biasing member magnetically interacts with the armature member to bias the armature member in one of the first and second positions. The magnetically active actuator is movable with respect to the switch portion between proximal and distal positions. The actuator magnetically interacts with the armature member when in the proximal position to move the armature to the other one of the first and second positions, and at least one of the armature member and the biasing member include a magnet.
U.S. Pat. No. 5,929,731 to Jackson, Jr. teaches a balanced magnetically-actuated proximity switch assembly for use in a monitoring system that includes a switch assembly and an actuating assembly. The switch assembly has a plurality of magnetic switches with respective magnetic directionalities. The actuating assembly is movable relative to the switch assembly and has a plurality of magnets. Each one of the magnets produces a magnetic field corresponding to the magnetic directionality of a respective one of the magnetic switches.
U.S. Pat. No. 7,248,136 to Habboosh teaches a universal magnetic switching assembly for detecting relative movement between first and second members, the universal switching assembly including, a flux directing device for selectively directing a majority of applied magnetic flux, such that an externally applied magnetic field cannot be used to defeat the magnetic switch assembly. The magnetic switching assembly also including at least one tamper switch to detect application of an external magnetic field.